package com.kamfu.usingfunctions.exercise02_12;

public class FunctionExamples {

  public static final Function<Integer, Integer> factorial0 = n -> n <= 1 ? n : n * FunctionExamples.factorial0.apply(n - 1);

  public static Function<Integer, Integer> factorial1;
  static {
    factorial1 = n -> n <= 1 ? n : n * factorial1.apply(n - 1);
  }

  public final Function<Integer, Integer> factorial2 = n -> n <= 1 ? n : n * this.factorial2.apply(n - 1);

  public Function<Integer, Integer> factorial3;
  {
    factorial3 = n -> n <= 1 ? n : n * factorial3.apply(n - 1);
  }

  public static void main(String[] args) {
    System.out.println(factorial0.apply(10));
    System.out.println(factorial1.apply(10));
    FunctionExamples x = new FunctionExamples();
    System.out.println(x.factorial2.apply(10));
    System.out.println(x.factorial3.apply(10));
  }
}
